Heretofore, in specially-equipped vehicles such as dump trucks, fire engines, etc., a PTO device is connected to the vehicle engine to supply power to a mounted device such as a pump or the like. For example, the PTO device is switched to a non-operating state when the vehicle running and power is supplied to the vehicle driving system. the PTO device is switched to an operational state when the vehicle is stopped and the mounted device is to be operated (PTO operation), and power is supplied to the mounted device.
Furthermore, the power required from PTO operations and vehicle running differs, and thus the engine control is desired to have variable mode for each case.
For example, in Japanese Laid-Open Patent Publication No. 2000-80934, a fuel control device has been proposed, in which control modes that are based on engine speed and the fuel supply quantity (injection quantity) are prepared individually for vehicle running and PTO operation. The control mode is switched between PTO operating mode and vehicle running mode in response to the ON-OFF PTO device switch. The control device of Japanese Laid Open Patent Publication No. 2000-80934 consists of a fuel injection map of the vehicle running, and a fuel injection map of PTO operation, which serves as the engine control when the PTO device is in operation.